TC Prep

TC Prep

TCs are two dissimilar metals joined by a welded bead. In order for a TC to read the temperature at any given point, the welded bead must come in direct contact with whatever you are measuring. The two dissimilar wires must remain separated and only joined at the bead; otherwise, your reading is no longer at the welded bead but wherever these two metals first make contact, rendering the reading invalid.

I have seen plenty of twisted TCs and TCs cut to length!

You will not get an accurate reading if your TC loses contact with the attachment material. The TC welded bead has to remain in direct contact with your component. A zigzagging TC reading on your profile graph is a sign of a loosely attached TC. This is why I am not a fan of TC probes since they can jump and bounce on the board. Twisting your TC, will also give you a false reading, since your TC will measure from the first twist or point of contact. I’ve seen plenty of TCs sticking out of solder or epoxy where this point of first contact is an inch off the PCB. In this case, you are measuring air!

Take the time-every time– to prep your TCs so that they remain apart and a welded bead remains in direct contact with your component. I use a hand pick and apply upward pressure toward the bead to separate the two wires. It will not break since it is a welded bead and should be solidly attached.